Food intake, assimilation efficiency, and growth of juvenile lizards Takydromus septentrionalis

The thermal dependence of food assimilation and locomotor performance in southern grass lizards, Takydromus sexlineatus (Lacertidae)

“…In this study, influence of body temperature on ADC and AE was very pronounced, but only lizards at 36 C had noticeably lower values of ADC and AE (Table 1), largely because they produced faeces that contained higher-energy contents as compared with those at lower body temperatures. Lizards at other six lower body temperatures had almost the same ADC and AE (Table 1), suggesting that T. sexlineatus be also a species whose digestive performance is less sensitive to variation in body temperature (Dutton et al, 1975;Waldschmidt et al, 1986;Ji and Wang, 1990;Van Damme et al, 1991;Beaupre et al, 1993;Ji et al, 1993Ji et al, , 1995Ji et al, , 1996Ji et al, , 1997Xu et al, 1999Xu et al, , 2001Du et al, 2000;Chen et al, 2003).…”

“…We burned dried samples in a WGR-1 adiabatic calorimeter (Changsha Instruments, China), and downloaded data in a computer. The assimilation efficiency was calculated as AE ¼ ðI À F À UÞ=I Â 100% (Ji et al, 1993), where I is the total energy consumed, F the energy in faeces and U the energy in urates. The apparent digestive coefficient was calculated as ADC ¼ ðI À FÞ=I Â 100% (Waldschmidt et al, 1986).…”

Cautionary notes on the descriptive analysis of performance curves in reptiles

“…With such variability, the ANOVA will always lead to a wide T o range. Large individual variability is expected especially when performance is not normalized (Huey and Stevenson, 1979) (i.e., expressed as a percentage of individual maxima) as it is the case in several recent studies (Ji et al, 1993(Ji et al, , 1996Du et al, 2000;Chen et al, 2003;McConnachie and Alexander, 2004;Zhang and Ji, 2004). Normalizing by individual controls for factors that systematically influence absolute performance (such as size or sex) and, thus, eliminates overall inter-individual variability.…”

“…One of their goals was to stimulate research in whole animal performance. In recent years, several laboratory studies have quantified the thermal reaction norms of organismal traits in reptiles (Ji et al, 1993;Witz and Lawrence, 1993;Scribner and Weatherhead, 1995;Ji et al, 1996;Du et al, 2000;Angilletta et al, 2002a;BlouinDemers et al, 2003;Chen et al, 2003;Elsworth et al, 2003;Zhang and Ji, 2004). Despite Huey and Stevenson's (1979) comprehensive discussion, however, we believe that the descriptive analysis of thermal reaction norms of reptiles in recent papers often provides incomplete information and, in some cases, is biologically misleading.…”

“…ANOVA is often used to analyse the effect of T b on performance in reptiles (Ji et al, 1993(Ji et al, , 1996Du et al, 2000;Angilletta et al, 2002a;Chen et al, 2003;Elsworth et al, 2003;Zhang and Ji, 2004). In general, the performance of several individuals is measured at various T b (usually 4-6) encompassing the range of T b experienced by the animal (i.e., within the CT).…”